Current File : //opt/alt/ruby21/lib64/ruby/2.1.0/rubygems/resolver.rb
require 'rubygems'
require 'rubygems/dependency'
require 'rubygems/exceptions'
require 'rubygems/util/list'
require 'uri'
require 'net/http'
##
# Given a set of Gem::Dependency objects as +needed+ and a way to query the
# set of available specs via +set+, calculates a set of ActivationRequest
# objects which indicate all the specs that should be activated to meet the
# all the requirements.
class Gem::Resolver
##
# If the DEBUG_RESOLVER environment variable is set then debugging mode is
# enabled for the resolver. This will display information about the state
# of the resolver while a set of dependencies is being resolved.
DEBUG_RESOLVER = !ENV['DEBUG_RESOLVER'].nil?
##
# Contains all the conflicts encountered while doing resolution
attr_reader :conflicts
##
# Set to true if development dependencies should be considered.
attr_accessor :development
##
# When true, no dependencies are looked up for requested gems.
attr_accessor :ignore_dependencies
##
# List of dependencies that could not be found in the configured sources.
attr_reader :missing
attr_reader :stats
##
# When a missing dependency, don't stop. Just go on and record what was
# missing.
attr_accessor :soft_missing
##
# Combines +sets+ into a ComposedSet that allows specification lookup in a
# uniform manner. If one of the +sets+ is itself a ComposedSet its sets are
# flattened into the result ComposedSet.
def self.compose_sets *sets
sets.compact!
sets = sets.map do |set|
case set
when Gem::Resolver::BestSet then
set
when Gem::Resolver::ComposedSet then
set.sets
else
set
end
end.flatten
case sets.length
when 0 then
raise ArgumentError, 'one set in the composition must be non-nil'
when 1 then
sets.first
else
Gem::Resolver::ComposedSet.new(*sets)
end
end
##
# Creates a Resolver that queries only against the already installed gems
# for the +needed+ dependencies.
def self.for_current_gems needed
new needed, Gem::Resolver::CurrentSet.new
end
##
# Create Resolver object which will resolve the tree starting
# with +needed+ Dependency objects.
#
# +set+ is an object that provides where to look for specifications to
# satisfy the Dependencies. This defaults to IndexSet, which will query
# rubygems.org.
def initialize needed, set = nil
@set = set || Gem::Resolver::IndexSet.new
@needed = needed
@conflicts = []
@development = false
@ignore_dependencies = false
@missing = []
@soft_missing = false
@stats = Gem::Resolver::Stats.new
end
def explain stage, *data # :nodoc:
if DEBUG_RESOLVER
d = data.map { |x| x.inspect }.join(", ")
STDOUT.printf "%20s %s\n", stage.to_s.upcase, d
end
end
def explain_list stage, data # :nodoc:
if DEBUG_RESOLVER
STDOUT.printf "%20s (%d entries)\n", stage.to_s.upcase, data.size
data.each do |d|
STDOUT.printf "%20s %s\n", "", d
end
end
end
##
# Creates an ActivationRequest for the given +dep+ and the last +possible+
# specification.
#
# Returns the Specification and the ActivationRequest
def activation_request dep, possible # :nodoc:
spec = possible.pop
explain :activate, [spec.full_name, possible.size]
activation_request =
Gem::Resolver::ActivationRequest.new spec, dep, possible
return spec, activation_request
end
def requests s, act, reqs=nil # :nodoc:
return reqs if @ignore_dependencies
s.dependencies.reverse_each do |d|
next if d.type == :development and not @development
reqs.add Gem::Resolver::DependencyRequest.new(d, act)
@stats.requirement!
end
@set.prefetch reqs
@stats.record_requirements reqs
reqs
end
##
# Proceed with resolution! Returns an array of ActivationRequest objects.
def resolve
@conflicts = []
needed = Gem::Resolver::RequirementList.new
@needed.reverse_each do |n|
request = Gem::Resolver::DependencyRequest.new n, nil
needed.add request
@stats.requirement!
end
@stats.record_requirements needed
res = resolve_for needed, nil
raise Gem::DependencyResolutionError, res if
res.kind_of? Gem::Resolver::Conflict
res.to_a
end
##
# Extracts the specifications that may be able to fulfill +dependency+ and
# returns those that match the local platform and all those that match.
def find_possible dependency # :nodoc:
all = @set.find_all dependency
matching_platform = select_local_platforms all
return matching_platform, all
end
def handle_conflict(dep, existing) # :nodoc:
# There is a conflict! We return the conflict object which will be seen by
# the caller and be handled at the right level.
# If the existing activation indicates that there are other possibles for
# it, then issue the conflict on the dependency for the activation itself.
# Otherwise, if there was a requester, issue it on the requester's
# request itself.
# Finally, if the existing request has no requester (toplevel) unwind to
# it anyway.
if existing.others_possible?
conflict =
Gem::Resolver::Conflict.new dep, existing
elsif dep.requester
depreq = dep.requester.request
conflict =
Gem::Resolver::Conflict.new depreq, existing, dep
elsif existing.request.requester.nil?
conflict =
Gem::Resolver::Conflict.new dep, existing
else
raise Gem::DependencyError, "Unable to figure out how to unwind conflict"
end
@conflicts << conflict unless @conflicts.include? conflict
return conflict
end
# Contains the state for attempting activation of a set of possible specs.
# +needed+ is a Gem::List of DependencyRequest objects that, well, need
# to be satisfied.
# +specs+ is the List of ActivationRequest that are being tested.
# +dep+ is the DependencyRequest that was used to generate this state.
# +spec+ is the Specification for this state.
# +possible+ is List of DependencyRequest objects that can be tried to
# find a complete set.
# +conflicts+ is a [DependencyRequest, Conflict] hit tried to
# activate the state.
#
State = Struct.new(:needed, :specs, :dep, :spec, :possibles, :conflicts) do
def summary # :nodoc:
nd = needed.map { |s| s.to_s }.sort if nd
if specs then
ss = specs.map { |s| s.full_name }.sort
ss.unshift ss.length
end
d = dep.to_s
d << " from #{dep.requester.full_name}" if dep.requester
ps = possibles.map { |p| p.full_name }.sort
ps.unshift ps.length
cs = conflicts.map do |(s, c)|
[s.full_name, c.conflicting_dependencies.map { |cd| cd.to_s }]
end
{ :needed => nd, :specs => ss, :dep => d, :spec => spec.full_name,
:possibles => ps, :conflicts => cs }
end
end
##
# The meat of the algorithm. Given +needed+ DependencyRequest objects and
# +specs+ being a list to ActivationRequest, calculate a new list of
# ActivationRequest objects.
def resolve_for needed, specs # :nodoc:
# The State objects that are used to attempt the activation tree.
states = []
while !needed.empty?
@stats.iteration!
dep = needed.remove
explain :try, [dep, dep.requester ? dep.requester.request : :toplevel]
explain_list :next5, needed.next5
explain_list :specs, Array(specs).map { |x| x.full_name }.sort
# If there is already a spec activated for the requested name...
if specs && existing = specs.find { |s| dep.name == s.name }
# then we're done since this new dep matches the existing spec.
next if dep.matches_spec? existing
conflict = handle_conflict dep, existing
return conflict unless dep.requester
explain :conflict, dep, :existing, existing.full_name
depreq = dep.requester.request
state = nil
until states.empty?
x = states.pop
i = existing.request.requester
explain :consider, x.spec.full_name, [depreq.name, dep.name, i ? i.name : :top]
if x.spec.name == depreq.name or
x.spec.name == dep.name or
(i && (i.name == x.spec.name))
explain :found, x.spec.full_name
state = x
break
end
end
return conflict unless state
@stats.backtracking!
needed, specs = resolve_for_conflict needed, specs, state
states << state unless state.possibles.empty?
next
end
matching, all = find_possible dep
case matching.size
when 0
resolve_for_zero dep, all
when 1
needed, specs =
resolve_for_single needed, specs, dep, matching
else
needed, specs =
resolve_for_multiple needed, specs, states, dep, matching
end
end
specs
end
##
# Rewinds +needed+ and +specs+ to a previous state in +state+ for a conflict
# between +dep+ and +existing+.
def resolve_for_conflict needed, specs, state # :nodoc:
# We exhausted the possibles so it's definitely not going to work out,
# bail out.
raise Gem::ImpossibleDependenciesError.new state.dep, state.conflicts if
state.possibles.empty?
# Retry resolution with this spec and add it's dependencies
spec, act = activation_request state.dep, state.possibles
needed = requests spec, act, state.needed.dup
specs = Gem::List.prepend state.specs, act
return needed, specs
end
##
# There are multiple +possible+ specifications for this +dep+. Updates
# +needed+, +specs+ and +states+ for further resolution of the +possible+
# choices.
def resolve_for_multiple needed, specs, states, dep, possible # :nodoc:
# Sort them so that we try the highest versions first.
possible = possible.sort_by do |s|
[s.source, s.version, s.platform == Gem::Platform::RUBY ? -1 : 1]
end
spec, act = activation_request dep, possible
# We may need to try all of +possible+, so we setup state to unwind back
# to current +needed+ and +specs+ so we can try another. This is code is
# what makes conflict resolution possible.
states << State.new(needed.dup, specs, dep, spec, possible, [])
@stats.record_depth states
explain :states, states.map { |s| s.dep }
needed = requests spec, act, needed
specs = Gem::List.prepend specs, act
return needed, specs
end
##
# Add the spec from the +possible+ list to +specs+ and process the spec's
# dependencies by adding them to +needed+.
def resolve_for_single needed, specs, dep, possible # :nodoc:
spec, act = activation_request dep, possible
specs = Gem::List.prepend specs, act
# Put the deps for at the beginning of needed
# rather than the end to match the depth first
# searching done by the multiple case code below.
#
# This keeps the error messages consistent.
needed = requests spec, act, needed
return needed, specs
end
##
# When there are no possible specifications for +dep+ our work is done.
def resolve_for_zero dep, platform_mismatch # :nodoc:
@missing << dep
unless @soft_missing
raise Gem::UnsatisfiableDependencyError.new(dep, platform_mismatch)
end
end
##
# Returns the gems in +specs+ that match the local platform.
def select_local_platforms specs # :nodoc:
specs.select do |spec|
Gem::Platform.installable? spec
end
end
end
##
# TODO remove in RubyGems 3
Gem::DependencyResolver = Gem::Resolver # :nodoc:
require 'rubygems/resolver/activation_request'
require 'rubygems/resolver/conflict'
require 'rubygems/resolver/dependency_request'
require 'rubygems/resolver/requirement_list'
require 'rubygems/resolver/stats'
require 'rubygems/resolver/set'
require 'rubygems/resolver/api_set'
require 'rubygems/resolver/composed_set'
require 'rubygems/resolver/best_set'
require 'rubygems/resolver/current_set'
require 'rubygems/resolver/git_set'
require 'rubygems/resolver/index_set'
require 'rubygems/resolver/installer_set'
require 'rubygems/resolver/lock_set'
require 'rubygems/resolver/vendor_set'
require 'rubygems/resolver/specification'
require 'rubygems/resolver/spec_specification'
require 'rubygems/resolver/api_specification'
require 'rubygems/resolver/git_specification'
require 'rubygems/resolver/index_specification'
require 'rubygems/resolver/installed_specification'
require 'rubygems/resolver/local_specification'
require 'rubygems/resolver/lock_specification'
require 'rubygems/resolver/vendor_specification'
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